This invention relates to image development in an electrostatographic copier or printer, and more particularly to an efficient, clean and inexpensive apparatus for replenishing or adding fresh toner to a development station in such a copier or printer.
In electrostatographic copiers and printers that produce or reproduce copies of images, it is well known to use toner particles, from a quantity of such particles held at a development station, to develop latent electrostatic images on an image-bearing member, for example, a photoconductor. As is also well known, the quantity of such toner particles being held at each development station is gradually depleted through such use, and therefore must be replenished periodically.
The replenishment of such toner particles, however, can be very inefficient, messy and, above all, expensive. This is because the toner particles, which usually consist of very fine thermoplastic particles that are pigmented, for example, with carbon black or other coloring pigments, are very susceptible to forming a toner or powder cloud, if they are blown or aerated. Such blowing or aeration is easily caused by mere grasping and handling of standard off-the-shelf toner containers which usually are made from plastic, and are therefore compressible. The powder or toner clouds formed as a result of such blowing or aeration, besides being messy, are also a problem in that they can migrate and contaminate other components inside the copier or printer.
In attempts to avoid some of these problems, various apparatus have been disclosed for replenishing or adding toner to the development station of an electrostatographic copier or printer. Such an apparatus is disclosed, for example, in commonly assigned U.S. application Ser. No. 944,105, filed Dec. 22, 1986 in the name of Thomas W. Mort, a co-inventor of this application. Although that disclosure represents an improvement over prior apparatus, it unfortunately still includes undesirable regrasping and direct rehandling of the toner container, after its inversion, in order to move it into a toner flow position. Such regrasping and rehandling of the container of course risks causing undesirable blowing or aeration of the toner.